Cooling unit



March 6, 1934. w. w. WILLIAMS ET AL 1,950,346

COOLING UNIT I Filed Feb. 15. 1933 3 sheets- -sheet 1 March 6, 1934. w. W. WILLIAMS El AL 1,9599345 COOLING UNIT Filed Feb. 15, 1935 s Sheets-Sheet 2 FE-E- a KW M A-lTTORYEYS.

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March 6, 1934.. w. w. WILLIAMS El AL 135G346 COOLING UNIT Filed Feb. 15, 1933 3 Sheets-Sheet 3 24 INVENTORS.

A TTORNEYS Patented Mar. 6, 1934 ATET,

COOLING IUNIT Walter W. Williams and Glenn F. Zellhoefer, Bloomington, 111.; said Zellhoefer assignor to Williams Oil-O-Matic Heating Corporation,

Bloomington, 111., a corporation of Illinois Application February 15,

1 Claim.

This invention relates to improvements in a cooling unit and more particularly to a device of this character employing a refrigerating system and circulating fan with means to maintain a high humidity in the air of a cold storage space and with means for maintaining the water in the refrigerating bath and for automatically purging saidwater bath of its accumulation of sludge.

Devices of this character are adaptable for use in meat and food storage rooms, cut-flower cases, and the like, where a high degree of humidity is desired as well as the maintenance of relatively low temperatures ranging from 35 to 40 F.

Cooling units for this purpose have employed refrigerating systems by circulating air over the evaporator of the system with the result that the relatively low temperature of the evaporator condenses the moisture contained in the air circulated over it and consequently results in dehydration or drying out of the air which in turn dehz drates the goods in the cold storage. In some forms the evaporators are provided with large finned surfaces providing maintenance of evaporator temperatures but slightly lower than the desired air temperature. This close temperature differential retards dehydration but that which does occur tends to dry out and shrink the stored goods. Circulating fans are also employed in connection with evaporators, but unless provision is made to provide moisture from an. outside source, drying out and shrinkage is more rapid than in cases wherenatural circulation is depended upon. Furthermore, the storage of boxes, crates, and relatively dry goods causes a further loss of moisture from the air in the storage space and deprives such moisture from the goo that are intended to be kept in a moist state.

It is an object of this invention to provide a cooling unit for the purpose explained above employing a circulating fan for circulating air throughout the refrigerated space and to maintain a high degree of humidity in the air in the cold storage space, and also to provide means for automatically flushing said bath of its accumulated sludge.

with these and other objects in view, refer ence is made to the accompanying sheets of drawings which illustrate a preferred form of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

In the drawings:

Figure 1 is a view in central vertical section coil of the heat exchanger.

1933, Serial No. 656,818

with parts shown in front elevation of a preferred form of this invention.

Figure 2 is a view in transverse section taken on the line 2-2 of Figure 1.

Figure '3 is a view in transverse section taken W on the line 33 of Figure 1. Figures 4 and 5 are enlarged detail views partly in section and partly in front elevation of the flushing and water replenishing means in the water tank illustrating the movement of this ap- 5 paratus in performing its function.

As shown in Figure 1 of the drawings this improved cooling unit includes a rectangular casing 1 supported on legs 2 preferably in the form of angle arms surrounding each exterior corner. 7 A motor M surrounded on its side and top by easing 3 is axially supported by hangers 4 from the top of the casing 1 and the top of the easing is enclosed by a conical closure 5 provided with an axial air discharge pipe 6. The bottom? of the casing l is closed by a bottom plate 7 having a depression which is cut out and provided with a closure plate 8, hereinafter described.

The bottom of the closure 1 forms a water tank and a circulating pump P is axially mounted therein upon hangers 9 depending from the motor hangers4. The operating shaft 10 of the motor is arranged axially of the casing 1 and is connected to the rotor of the pump P. A heat exchanger in the form of the coils 11 is hung upon brackets 12 secured to the pump brackets 9 above the pump P. The discharge side of the pump P is connected by the pipe 13 to the lower The heat exchanger includes two tubes, one within the other, and in the construction illustrated, the water from the pump P is circulated through the smaller tube while the outer tube is connected at its upper end by the pipe 14 through the expansion valve V to the high side of a refrigerating unit, and at its lower end by the pipe 15 to the low side of said unit wherebythe refrigerating element is circulated through the heat exchanger in the same manner as in an evaporator.

A centrifugal fan, of the multiblade type, having vertical blades 16 and a top cover plate 17 is mounted on the motor operating shaft 10 adjacent the motor and within the pump hangers 9. A pipe 18 connects the upper end of the water pipe of the heat exchanger to a circular chamber 19 mounting a plurality of vertical discharge pipes 20 in communication therewith and adjacent to the inner edges of the blades 16 and terminating short of the cover plate17. Each of the said discharge pipes 20 is provided with a plurality of discharge openings for discharging the water therethrough in the form of a spray between the blades 16 and upon the top cover plate 1'7.

A collecting chamber for the water discharged from the pipes 20 is provided in the form of a cylindrical casing 21 suspended from the upper sides of the casing 1 and provided with a convex bottom 22 having a cylindrical opening just below the fan embracing the pump hangers 9 and provided with a plurality of discharge openings 23 adjacent the outer walls of the exterior casing 21. The walls of the exterior casing 1 are provided with a plurality of air intakes or openings 24 whereby surrounding air is drawn from the bottom of cold storage room into the interior and through the opening in the bottom of plate 22 by the operation of the fan which air is then discharged through the pipe 6 at the top of the casing.

In this device it is necessary that a certain amount of water always be maintained in the water compartment and maintained above the level of the pump P. Upon operation of the motor, water is circulated by the pump P through the heat exchanger where its temperature is reduced by the circulation of the refrigerant and is then discharged in the form of a spray through the discharge pipes 20 and thereafter collects in the bottom of the collecting chamber and descends through the openings 23 in the form of a wall of water into the water tank. Surrounding air is drawn through the opening in plate 22 and forced through the wall of water descending from the collecting chamber and then discharged through the water spraying from the discharge pipes 20 by the action of the fan whereby the air is not only cooled, but its humidity is maintained at the saturation point. The action of the fan also delivers the refrigerated air through the pipe 6 to the cold storage compartment.

During this operation, a certain amount of excess water is accumulated by the precipitation from warm air entering the cold storage space, and during the operation the dust, dirt, food particles, etc. are washed out of the air during its passage through the wall of water and spray, which dirt, dust, food particles, etc. collect in the form of a sludge at the bottom of the water tank and unless periodically removed, causes injury and loss of efllciency to the heat exchanger; also it may become odoriferous.

For the purpose of automatically removing the excess water accumulated by precipitation and automatically flushing the bottom of the water tank, the plate 8 closing the depression in the bottom 7 of the water tank is provided with a depending valve casing 24 having a valve seat flush with the upper side of the plate and mounting a reciprocable valve 25 having a depending guiding stem travelling through a guiding spider upon the interior of casing 24 which is adapted to co-act with the valve seat. The other end of the valve is in communication with a pipe 26 leading to the sewer. An over-flow pipe 27 connected with the waste pipe 26 passes vertically through the plate 8, secured thereto, and extending above the normal water level to prevent the flooding of the water tank.

Referring to Figures 4 and 5, the valve 25 is operated to open and close by the rise and fall of a vertical guide 29 pivotally mounted at each end to the respective ends of two parallel arms 30 and 31 pivoted to a vertical supporting member a 32 mounted upon the upper side of the plate 8.

Adjustable stops 33 are mounted upon the guide rod 29 to limit the movement of the float 28 thereover. The upper pivoted arm 30 mounts an adjustable counter weight 34 on the side of its pivot opposite the float to regulate the sensitiveness of the operation of the float. The lower pivoted arm 31 passes between the arms of a U- shaped bracket 35 carried on the upper side of the valve 25 and is connected thereto by pin 36 having a lost motion connection so that as the arm 31 rotates about its pivot, the valve 25 is raised or lowered over its seat. The arm 31 is extended to the left of its pivot upon the support 32 and its vertical edge is provided with two indentations adapted to be engaged by the spring pressed pawl 37 carried on the lever 38 pivoted at the lower end to the bracket 39 extending from the support 32. These indentations are so spaced apart that they will be engaged and hold the arm 35 against movement when the valve is seated and when the valve is open to its fullest extent.

This device is intended to be operated within the storage space which it is intended to supply with cool humid air so that, for example, if this unit is installed in a meat cooler, it should be understood that the mean air temperature in such cooler is one to three degrees higher than the air discharged from the cooling unit and it should be 105 understood that while the air leaving the cooling unit has a relative humidity of one hundred percent, the mean relatlve humidity in the meat cooler will be slightly lower, due to its slight increase in temperature.

If outside temperature remained constant, and if no leakage of heat, air or moisture occurred, an equilibrium of temperature and humidity would soon be established, and remain constant. However, in practice, such is not the case. Out- 115 side temperatures do vary, and doors of the meat cooler must be opened to store and to remove the refrigerated goods, resulting in a disturbance of this equilibrium. For instance, each time a door is opened, warm air enters and displaces an equal amount of refrigerated air. The air entering is certainly warmer, and may be of a lower relative humidity, but upon being chilled by its passage through the cooling unit, the moisture contained therein is more than the air will hold at its reducedtemperature, and excess moisture is condensed out, and combines with the water spray. Storing of warm moist meat, and other goods has the same eflect of adding moisture in the form of condensation to the air drawn into the cooling and humidifying umt through the openings 24. The raising of the original water level by this accumulation of moisture supplies the means of operating the float 28 shown in detail on Figures 4 and 5.

Figure 4 illustrates in full lines the position of the float about to contact the upper stop 33 after the lever'31 has been depressed to close the valve 25 and its lower' notch engaged with the spring pressed pawl 37, maintaining the valve in closed 140 position. Upon accumulation of the removed excess moisture of the air in the water tank, the water level therein will rise thereby causing the float 28 to engage the upper stop and rotate the lever 31 about its pivot lifting the valve 25 145 off of its seat and causing the upper notch of the lever to be engaged by the spring pressed pawl 3'7, as shown in dotted lines in Figure 4, whereupon the water will be discharged through the open valve and flush the bottom of the tank 150 as it passes therethrough on its way to the sewer. As the water level decreases, the float will descend upon its guide 29 until it engages the bottom stop 33 thereon, as shown in dotted lines in Figure 5. Thereafter, as the water level lowers, the weight of the float will rotate the lever 31 to snap it out of engagement with the pawl 37 until I the valve is closed and the pawl engages its lower notch in the same manner as shown in full lines in Figure 4. The position of the float at the time the valve is closed is shown in dotted lines inFigure 5. The mechanism is so constructed that the valve is closed before the intake side of the pump P is uncovered.

To provide for immediately replenishing some of the water used in flushing the bottom of the tank, a. water supply pipe 40 is mounted upon the closure plate 8 to pass therethrough and be connected to a. water supply. The other end is connected to a valve casing 41 preferably mounted upon the support 32 which mounts a. valve seat 42 and a float operated reciprocating valve 43 in the manner shown in detail in Figure 4.

As long as the water level is above the operatingat the bottom to form a water tank and having an air discharge at the top with air intakes in the sides thereof, a water collecting chamber having walls spaced apart from the casing in communication with the air discharge and having a central air inlet in the bottom, a centrifugal fan comprising a top closure plate and annular-1y arranged vertical blades depending therefrom, arranged within the casing with its lower end passing through the central bottom opening, a heat exchanger interposed between the water tank and bottom of said chamber including a coil of pipe, a. cooling coil of larger diameter arranged aboutthe first coil with the ends of the larger coil connected to a source of refrigeration, a pump located in the water tank below the heat exchanger and having its discharge port connected with the lower end of said coil of smaller pipe, a plurality of vertical pipes arranged within the blades of the fan having spraying nozzles in the sides adjacent the vanes andathe lower end of each pipe connected to the upper coil of said smaller pipe, and a plurality of openings arranged concentrically in the bottom of the water collecting chamber adjacent the sides thereof, and means for simultaneously operating the fan and pump whereby the water in the tank is circulated through the smaller coils and the cooled water 00 discharged in a spray through the blades of the fan, the sprayed water collected on the bottom of the chamber returning to the tank in the form of a continuous wall surrounding the cooler coils whereby the air entering the'casing intakes is drawn through the descending wall of water from the chamber and is forced-through the fan blades together with the sprayed water and thereafter circulated through the spray in the chamber and the cooled and humidified air delivered through the discharge at the top of the casing.

WALTER W. WILLIAMS. GLENN F. ZEILHOEFER. 

